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Head Grunt
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Friend installs a 200 amp underground service with pedestal for a friend of his that he used to work with. From there it went about 200' through the woods to another 100amp sub panel that a mobile home was to be connected to. Now this project has been all summer long and during this time the owner has lost this future home and property to his now ex-wife so the owner just wants to get things turned on when the home arrives and be done per their divorce agreement. So this mobile home arrives and is set, my friend goes over and wires it in. He calls me asking to come look at it as he has light bulbs popping, tv's are burned up, fridge burned up and who knows what else is wrong. I tell him to check his neutral and claims it is fine but he keeps getting odd voltages, surges and he has power between the ground buss and neutral buss. I am like WTF has he done??? So i go over and meet him, start checking from the meter back. I get into the house and i find he had put the neutral on the ground buss but no bond screw. Also the panel was not grounded. So i had to explain to him that this is a sub panel and the grounds/neutrals are to be separated and he needs to run 4 wire from the outdoor sub panel in to the mobile home. I also explained that doing what he did he created a circuit between phases creating the surge of power burning up whatever appliances/devices that were on. It took me quite some time to explain the difference between the use of 3-wire and 4-wire, when and where they are to be used and even why.

I still do not think he grasped it all. This guy has been building homes for yrs, does great electric work himself when wiring a home, knows everything about building a home from cutting the 1st tree to cleaning the last window when finished. He worked for a wealthy man for 27yrs doing all his bidding but finally quit to work for himself and this is one of his 1st job he took on and finished. I just hope he has insurance because the owners ex-wife is after both of them for the cost to replace everything that burned up. Not a good way to start your own business.
 

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He sure did. Don't they inspect the service entrance around there? I wired my own mobile home once and had to have it inspected and signed off before they would energize it.
 

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so as I picture it- What he had in the Mobil home was two hots with no neutral and the ground loosely connected to neutral. Voltage would vary on the 120circuts as the balance of the load shifted such that the circuit with the higher load got the lower voltage?

If the motor home ground and neutral were all tightly bonded to the outdoor sub panel neutral would he have solid steady voltages without proper safe grounding? In other words would have functioned without being safe or legal? Or would local grounding rod be required to anchor the neutral in the middle of the 240?
 

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The Ultimate Wire Hider
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His biggest mistake was that he assured himself that it was "fine" when every other indication showed that it wasn't.

It's like every time a friend or family member calls me up with a problem, I know EXACTLY what they did wrong and they swear up and down that they did it right. Then when I get over there, it's exactly as I thought it was.

I'm at the point now where I just say, "I'll be right over." because I'll have to go over there anyway after spending an hour talking them through it.
 

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I own stock in FotoMat!
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A ground rod would not help at all.

Grounding electrodes and grounding conductors are two totally separate animals. They are not interchangeable.
 

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Electrical Contractor
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This guy has been building homes for yrs, does great electric work himself when wiring a home, knows everything about building a home from cutting the 1st tree to cleaning the last window when finished.
Obviously not. :whistling:

Even residential electrical work is far more than wiring receptacles and lights.

NO ONE can be a pro at everything involved with building a house. Some things are better left to the professionals in their respective trades, regardless of how good someone thinks they are.
 

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Obviously not. :whistling:

Even residential electrical work is far more than wiring receptacles and lights.

NO ONE can be a pro at everything involved with building a house. Some things are better left to the professionals in their respective trades, regardless of how good someone thinks they are.

Unless you're a 12-year-old 'of limited mental capacity'. :whistling
 

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Always Learning
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Just curious what you mean by pedestal. A utility pedestal, a 200 amp panel, or a disconnect after a meter? Is the meter on the mobile home or at the road? Curious for my own knowledge if that changes the need from 3 wire to 4 wire? Around my area only three wire would be ran from a pedestal with a separate grounding rod at the meter location. Our utility company grounds their neutral at the transformer and doesn't require to separate grounds and neutrals in the panel.
 

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Just curious what you mean by pedestal. A utility pedestal, a 200 amp panel, or a disconnect after a meter? ........
Short answer: Any of the above.

A pedestal is basically any version of an above-ground splice/junction box. It may or may not have a meter, or a disconnect, or fuses, or other manner of electrical apparatus attached to it.

It may be owned by the utility, political subdivision (city, county, etc.) or the property owner.
 

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Friend installs a 200 amp underground service with pedestal for a friend of his that he used to work with. From there it went about 200' through the woods to another 100amp sub panel that a mobile home was to be connected to. Now this project has been all summer long and during this time the owner has lost this future home and property to his now ex-wife so the owner just wants to get things turned on when the home arrives and be done per their divorce agreement. So this mobile home arrives and is set, my friend goes over and wires it in. He calls me asking to come look at it as he has light bulbs popping, tv's are burned up, fridge burned up and who knows what else is wrong. I tell him to check his neutral and claims it is fine but he keeps getting odd voltages, surges and he has power between the ground buss and neutral buss. I am like WTF has he done??? So i go over and meet him, start checking from the meter back. I get into the house and i find he had put the neutral on the ground buss but no bond screw. Also the panel was not grounded. So i had to explain to him that this is a sub panel and the grounds/neutrals are to be separated and he needs to run 4 wire from the outdoor sub panel in to the mobile home. I also explained that doing what he did he created a circuit between phases creating the surge of power burning up whatever appliances/devices that were on. It took me quite some time to explain the difference between the use of 3-wire and 4-wire, when and where they are to be used and even why.

I still do not think he grasped it all. This guy has been building homes for yrs, does great electric work himself when wiring a home, knows everything about building a home from cutting the 1st tree to cleaning the last window when finished. He worked for a wealthy man for 27yrs doing all his bidding but finally quit to work for himself and this is one of his 1st job he took on and finished. I just hope he has insurance because the owners ex-wife is after both of them for the cost to replace everything that burned up. Not a good way to start your own business.
Woodchuck..... Interesting....but had a little confusion understanding what was connected to what....

Does this not just reduce to he had a broken (never connected) neutral in his service feed to the mobile home (or subpanel in this case).

Thanks...Peter
 

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Always Learning
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480sparky said:
Short answer: Any of the above.

A pedestal is basically any version of an above-ground splice/junction box. It may or may not have a meter, or a disconnect, or fuses, or other manner of electrical apparatus attached to it.

It may be owned by the utility, political subdivision (city, county, etc.) or the property owner.
Ok. Why would some utility companies require 4 wire from a pedestal and some 3? If a ground is provided at the pedestal and the panel what's the need for 4 wire?
 

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Ok. Why would some utility companies require 4 wire from a pedestal and some 3? If a ground is provided at the pedestal and the panel what's the need for 4 wire?
Basic rule: Past the 'first point of disconnect' (main fuse or breaker), the ground and neutral must be kept separate.
 

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480sparky said:
Basic rule: Past the 'first point of disconnect' (main fuse or breaker), the ground and neutral must be kept separate.
Gotcha...so after a fused/breakered disconnect. But if the utility pedestal is just a non-breakered junction for the utility company, that's why it's a 3 wire. Thanks!
 

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overanalyze said:
Gotcha...so after a fused/breakered disconnect. But if the utility pedestal is just a non-breakered junction for the utility company, that's why it's a 3 wire. Thanks!
I think it depends where you are. The electric panel for my mobile home had to have the equipment ground and neutral separated in the panel. Even though it was coming straight from the transformer not from another panel. The electrical inspector explained to me why but I didn't really follow.
 

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I think it depends where you are. The electric panel for my mobile home had to have the equipment ground and neutral separated in the panel. Even though it was coming straight from the transformer not from another panel. The electrical inspector explained to me why but I didn't really follow.
I assume you are saying the neutral was floated out of the main......not just the BI wanted grounds and neutrals on different bars.

Kenn.... So where was the EGC going to......

are you sure the neutral and egc were not bonded at the meter box.
 

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I think it depends where you are. The electric panel for my mobile home had to have the equipment ground and neutral separated in the panel. Even though it was coming straight from the transformer not from another panel. The electrical inspector explained to me why but I didn't really follow.

No meter?

Is there fuses or a disco at the meter?
 

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The Duke
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So just out of curiosity (and if I'm following the explanation correctly) what happens if both the pedestal and sub panel is grounded, and only 3 wire used from pedestal to sub panel? I recall hooking up a 220 compressor that had 3 wire. Essentially 2 hots and a ground(?) How is that any different than the situation described?
 

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So just out of curiosity (and if I'm following the explanation correctly) what happens if both the pedestal and sub panel is grounded, and only 3 wire used from pedestal to sub panel? I recall hooking up a 220 compressor that had 3 wire. Essentially 2 hots and a ground(?) How is that any different than the situation described?

The house needs a neutral (intended to carry current under normal use) in order to get 120v. Your 220v compressor doesn't need a neutral, just a ground.
 
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220v switches between positive and negative 60 times a second or so, so one leg will be the neutral and then the other leg will be neutral. That's why it doesn't need a separate neutral. But some appliances like stoves need a neutral also (4 wire) cause the clock runs on 110v (one leg of 220v)
 

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220v switches between positive and negative 60 times a second or so,...
120 times, not 60. And 110v does the same thing. So does 208 volts, 277 volts, 480 volts.......


..........so one leg will be the neutral and then the other leg will be neutral....
:laughing: Um, no.


That's why it doesn't need a separate neutral.
Now I've heard everything!


.....But some appliances like stoves need a neutral also (4 wire) cause the clock runs on 110v (one leg of 220v)
Well, 1 out of four ain't bad.
 
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